International Journal of Automotive Technology

The Korean Society of Automotive Engineers (한국자동차공학회)
권호 표지

EFFECTS OF A SPLIT INJECTION ON SPRAY CHARACTERISTICS FOR A COMMON-RAIL TYPE DIESEL INJECTION SYSTEM

  • PARK S. W. (Graduate School of Hanyang University) ;
  • SUH H. K. (Graduate School of Hanyang University) ;
  • LEE C. S. (Department of Mechanical Engineering, Hanyang University)
  • Published : 2005.06.01
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Abstract

This work was performed to investigate the effect of a split injection on spray characteristics of fuel sprays injected from a common rail system. In order to analyze the spray behavior and atomization characteristics at various rates of split injections, the injection durations of pilot and main injections were varied in experiments. The injection rate of split injection was measured to study the effect of the pilot injection on the main injection. By using a Nd:YAG laser and an ICCD camera, the development of the injected spray was visualized at various elapsed time from the start of injection. The microscopic characteristics such as SMD and axial velocity were analyzed by using a phase Doppler particle analyzer system. The results indicate that the ambient gas flow generated by the pilot injection affects the behavior of main spray, whereas the effect of pressure variation on the main spray is little. The spray tip penetration of a main spray with pilot injection is longer than that of the single injection by the effect of ambient gas flow. Also the main spray produces larger droplets than the pilot spray due to a small relative velocity between the droplets and ambient gas.

Keywords

References

  1. Assanis, D. N., Filipe, Z. S., Fiveland, S. B. and Syrimis, M. (2000). A methodology for cycle-by-cycle transient heat release analysis in a turbocharged direct-injection diesel engine. SAE Paper No. 2000-01-1185
  2. Bianchi, G. M., Falfari, S., Pelloni, P., Kong S. C. and Reitz, R. D. (2002). Numerical analysis of highpressure fast-response common rail injector dynamics. SAE Paper No. 2002-01-0213
  3. Bosch, W. (1996). The fuel rate indicator: A new measuring instrument for display of the characteristics of individual indicator. SAE Paper No. 660749
  4. Carlucci, P., Ficaralla, A. and Laforgia, D. (2003). Effect of pilot injection parameters on combustion for common rail diesel engines. SAE Paper No. 2003-01-0700
  5. Demoulin, F. X. and Borghi, R. (2002). Modeling of turbulent spray combustion with application to diesel like experiment. Combustion and Flame, 129, 281-293 https://doi.org/10.1016/S0010-2180(02)00340-1
  6. Gao, Z. and Schreiber, W. (2001). The effects of EGR and split fuel injection on diesel engine emission. Int. J. Automotive Technology 2, 4, 123-133
  7. Henein, N. A., Lai, M. C., Singh, I. P., Zhong, L. and Han, J. (2002). Characteristics of a common rail diesel injection system under pilot and post injection modes. SAE Paper No. 2002-01-0218
  8. Ikegami, M., Nakatani, K., Tanaka, S. and Yamane, K. (1997). Fuel injection rate shaping and its effect on exhaust emissions in a direct-injection diesel engine using a spool acceleration type injection system. SAE Paper No. 970347
  9. Lee, C. S. and Park, S. W. (2002). An experimental and numerical study on fuel atomization characteristics of high-pressure diesel injection sprays. Fuel 81, 18, 2417-2423 https://doi.org/10.1016/S0016-2361(02)00158-8
  10. Minami, T., Takeuchi, K. and Shimazaki, N. (1995). Reduction of diesel engine NOx using pilot injection. SAE Paper No. 950611
  11. Nehmer, D. A. and Reitz, R. D. (1994). A study of pilot injection in a Dr diesel engine. SAE Paper No. 940668
  12. Park, S. W. and Lee, C. S. (2003). Macroscopic structure and atomization characteristics of high-speed diesel spray. Int. J Automotive Technology 4, 4, 157-164
  13. Zhang, L. (1999). A study of pilot injection in a DI diesel engine. SAE Paper No. 1999-01-3493